Learning To Crop Gấc

My first gấc fruit, Momordica cochinchinensis.

Pleased to report that cuttings taken from my gấc, Momordica cochinchinensis  have struck. There are challenges to growing this tropical vine…starting with finding seed.
Gấc, Momordica cochinchinensis, is a tropical fruit related to bitter melon (M. charantia). I saw my first gấc on sale in a tea plantation in Srimangal, Bangladesh. Native from SE Asia and China through Indonesia to far northern Queensland, gấc is a traditional food and medicinal plant.

The soft, fleshy aril surrounding the seed are used to colour and flavour rice. It tastes somewhat like concentrated tomato.

Across Vietnam, gấc rice (xôi gấc) is served for the New Lunar Year.  The aril may also gently fried in cooking oil (see below) which absorbs the vibrant colour and rich flavour so that when you subsequently cook other foods, the gac oil imparts its colour and flavour. Gấc oil extends the usefulness of a crop with a short picking season and which doesn’t store well when fresh.

Unfortunately, the ‘wellness’ industry has started exploiting products containing gấc. Gấc is certainly high in phytonutrients: it has fifty to seventy times as much lycopene as the best tomatoes, but it is unlikely to cure cancers. 

I know of no Australian source of seed, either through commerce or seed saving networks. In 2016, I found a ripe fruit up a rainforest tree on a roadside in Mossman. It shared its support with a native yam and it was the yam that caught my attention.

Gấc seed, Momordica cochinchinensis.

The seed germinated and all went well until I discovered that caterpillars in the genus Spodoptera can strip a vine bare in a few days. Attacks follow summer rain and storms. Control with Dipel, pyrethrum or a spraying oil works well, but you have to be prompt and thorough.

So far, only carpenter bees seem interested in the flowers, so I am the bee. I pollinate by hand.

Space is an issue in a home garden, because gấc is a sun-loving vine growing as large as a passionfruit, only faster.

Gấc is also dioecious, so expect to wait 8 – 18 months (in Brisbane) for vines to mature and bloom so you can identify individuals by gender. That done, I culled excess male plants to give the females more space.

Seed is a lottery and a batch of seedlings take time and considerable space to declare their gender, so propagating female plants by cutting is advantageous. My partner, a Vietnamese market gardener, tells me this approach is unconventional.

Female gấc cuttings, Momordica cochinchinensis.

I’ll let the cuttings develop a reasonable root system before potting on individually.

In 2019, I produced one fruit. By 2022, I hope to be able to produce a reasonable crop of fruit and seed for sharing.

For further information about Momordica cochinchinensis, click on this link.

Jerry Coleby-Williams
Director, Seed Savers’ Network Inc.
31st January 2020

2 Comments Add yours

  1. Hello in there, Jerry. I just wanted to let you know that some time (within the last few years) I was visiting an old friend who was holidaying in Byron Bay. When we arrived, she’d come back from Byron Bay grower’s market, and had some Gac fruit with her. I’d never heard of it, and googled it whilst at her holday place. She knows that I love propagating almost anything useful, so she gave me a small taste of the fruit and then offered me the seeds. It was definitey the right plant, as the seeds are quite unique. Sadly, somehwere in my chaotic lack of defined seed-raising area, the Gac seeds were lost, but I thought anyone interested in this post might like to try their luck at the Byron Markets. Whoever sold the fruit on that occasion may still have either seeds or cuttings available. Thank you for your always inspirating posts.

    1. Thank you for the lead 🙂

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